| // |
| // Copyright 2018 The Abseil Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| |
| #include "absl/debugging/internal/examine_stack.h" |
| |
| #ifndef _WIN32 |
| #include <unistd.h> |
| #endif |
| |
| #include <csignal> |
| #include <cstdio> |
| |
| #include "absl/base/attributes.h" |
| #include "absl/base/internal/raw_logging.h" |
| #include "absl/base/macros.h" |
| #include "absl/debugging/stacktrace.h" |
| #include "absl/debugging/symbolize.h" |
| |
| namespace absl { |
| namespace debugging_internal { |
| |
| // Returns the program counter from signal context, nullptr if |
| // unknown. vuc is a ucontext_t*. We use void* to avoid the use of |
| // ucontext_t on non-POSIX systems. |
| void* GetProgramCounter(void* vuc) { |
| #ifdef __linux__ |
| if (vuc != nullptr) { |
| ucontext_t* context = reinterpret_cast<ucontext_t*>(vuc); |
| #if defined(__aarch64__) |
| return reinterpret_cast<void*>(context->uc_mcontext.pc); |
| #elif defined(__arm__) |
| return reinterpret_cast<void*>(context->uc_mcontext.arm_pc); |
| #elif defined(__i386__) |
| if (14 < ABSL_ARRAYSIZE(context->uc_mcontext.gregs)) |
| return reinterpret_cast<void*>(context->uc_mcontext.gregs[14]); |
| #elif defined(__mips__) |
| return reinterpret_cast<void*>(context->uc_mcontext.pc); |
| #elif defined(__powerpc64__) |
| return reinterpret_cast<void*>(context->uc_mcontext.gp_regs[32]); |
| #elif defined(__powerpc__) |
| return reinterpret_cast<void*>(context->uc_mcontext.regs->nip); |
| #elif defined(__s390__) && !defined(__s390x__) |
| return reinterpret_cast<void*>(context->uc_mcontext.psw.addr & 0x7fffffff); |
| #elif defined(__s390__) && defined(__s390x__) |
| return reinterpret_cast<void*>(context->uc_mcontext.psw.addr); |
| #elif defined(__x86_64__) |
| if (16 < ABSL_ARRAYSIZE(context->uc_mcontext.gregs)) |
| return reinterpret_cast<void*>(context->uc_mcontext.gregs[16]); |
| #else |
| #error "Undefined Architecture." |
| #endif |
| } |
| #elif defined(__akaros__) |
| auto* ctx = reinterpret_cast<struct user_context*>(vuc); |
| return reinterpret_cast<void*>(get_user_ctx_pc(ctx)); |
| #endif |
| static_cast<void>(vuc); |
| return nullptr; |
| } |
| |
| // The %p field width for printf() functions is two characters per byte, |
| // and two extra for the leading "0x". |
| static constexpr int kPrintfPointerFieldWidth = 2 + 2 * sizeof(void*); |
| |
| // Print a program counter, its stack frame size, and its symbol name. |
| // Note that there is a separate symbolize_pc argument. Return addresses may be |
| // at the end of the function, and this allows the caller to back up from pc if |
| // appropriate. |
| static void DumpPCAndFrameSizeAndSymbol(void (*writerfn)(const char*, void*), |
| void* writerfn_arg, void* pc, |
| void* symbolize_pc, int framesize, |
| const char* const prefix) { |
| char tmp[1024]; |
| const char* symbol = "(unknown)"; |
| if (absl::Symbolize(symbolize_pc, tmp, sizeof(tmp))) { |
| symbol = tmp; |
| } |
| char buf[1024]; |
| if (framesize <= 0) { |
| snprintf(buf, sizeof(buf), "%s@ %*p (unknown) %s\n", prefix, |
| kPrintfPointerFieldWidth, pc, symbol); |
| } else { |
| snprintf(buf, sizeof(buf), "%s@ %*p %9d %s\n", prefix, |
| kPrintfPointerFieldWidth, pc, framesize, symbol); |
| } |
| writerfn(buf, writerfn_arg); |
| } |
| |
| // Print a program counter and the corresponding stack frame size. |
| static void DumpPCAndFrameSize(void (*writerfn)(const char*, void*), |
| void* writerfn_arg, void* pc, int framesize, |
| const char* const prefix) { |
| char buf[100]; |
| if (framesize <= 0) { |
| snprintf(buf, sizeof(buf), "%s@ %*p (unknown)\n", prefix, |
| kPrintfPointerFieldWidth, pc); |
| } else { |
| snprintf(buf, sizeof(buf), "%s@ %*p %9d\n", prefix, |
| kPrintfPointerFieldWidth, pc, framesize); |
| } |
| writerfn(buf, writerfn_arg); |
| } |
| |
| void DumpPCAndFrameSizesAndStackTrace( |
| void* pc, void* const stack[], int frame_sizes[], int depth, |
| int min_dropped_frames, bool symbolize_stacktrace, |
| void (*writerfn)(const char*, void*), void* writerfn_arg) { |
| if (pc != nullptr) { |
| // We don't know the stack frame size for PC, use 0. |
| if (symbolize_stacktrace) { |
| DumpPCAndFrameSizeAndSymbol(writerfn, writerfn_arg, pc, pc, 0, "PC: "); |
| } else { |
| DumpPCAndFrameSize(writerfn, writerfn_arg, pc, 0, "PC: "); |
| } |
| } |
| for (int i = 0; i < depth; i++) { |
| if (symbolize_stacktrace) { |
| // Pass the previous address of pc as the symbol address because pc is a |
| // return address, and an overrun may occur when the function ends with a |
| // call to a function annotated noreturn (e.g. CHECK). Note that we don't |
| // do this for pc above, as the adjustment is only correct for return |
| // addresses. |
| DumpPCAndFrameSizeAndSymbol(writerfn, writerfn_arg, stack[i], |
| reinterpret_cast<char*>(stack[i]) - 1, |
| frame_sizes[i], " "); |
| } else { |
| DumpPCAndFrameSize(writerfn, writerfn_arg, stack[i], frame_sizes[i], |
| " "); |
| } |
| } |
| if (min_dropped_frames > 0) { |
| char buf[100]; |
| snprintf(buf, sizeof(buf), " @ ... and at least %d more frames\n", |
| min_dropped_frames); |
| writerfn(buf, writerfn_arg); |
| } |
| } |
| |
| } // namespace debugging_internal |
| } // namespace absl |